The True Heroes
by madgirlmuahaha
Summary: In the face of mortal danger and tragedy, there's little we can do other than cling to what little hope there is and rise up to become heroes. A one-shot about Alphys and Undyne rising up to be the true heroes of the Underground during a genocide run. Rated T because it's during Genocide run.


"Quickly, now! Everybody get down to the basement!" Alphys shouted at the top of her lungs. The lab was packed with monsters, all of them frenzied, bewildered, and afraid.

"Like, move over!"

"There's, like, no room _to_ move over!"

"Ha…this isn't funny at all…."

"Mommy, I miss Snowdin…"

Someone pounded at the door. Alphys jumped about half a foot in the air and froze. She could feel her heartbeat accelerating at an unnatural pace.

Had the human already made it's way to Hotland?

She heard someone shouting from the other side, "ALPHYS! I'VE GOT THE LAST OF THE SURVIVORS!"

Alphys gasped and hit the button to open the door. Undyne staggered in with half a dozen little Tems clinging onto her arms and legs.

"Temmie is afraid," one of them said, looking up at Alphys with wide eyes and shivering with fright.

"Don't worry," Alphys tried to comfort her, "Temmie will be safe here. Now all of you, get into the elevator!"

The Tems scattered and climbed on top of other monsters to fit in the elevator. Alphys pulled the switch, and the elevator descended, bringing all of the refugees inside to the one place that gave the illusion of safety.

Now, it was just Alphys and Undyne in the room.

"So, what's the situation look like?" Alphys asked in a grave tone.

Undyne sighed. "Bad. Like, really, _really_ bad. I'm just happy I got all the survivors from Waterfall out before the human got to them."

"What are we going to do?"

Undyne stared for a moment at Alphys. What _could_ they do? That… _thing_ was unstoppable. There was a reason why Papyrus and Sans had been stationed right near where the Ruins were. Undyne had trained Papyrus herself, and knew just what he was capable of. The one thing that prevented him from showing his true strength in battle was his other true strength—his kind heart and unwavering belief in the good in others. Even if he refused to physically attack you, he'd win you over with his faith in you.

That was how he'd won Undyne's friendship. Nothing natural could defeat Papyrus. That is, nothing that wasn't a heartless killer bent on bringing nothing but destruction to the Underground.

That… _human._

"I'm going to stop it."

Alphys gasped. "Undyne! That human will _KILL YOU!_ There's too much power there! You won't be able to…to…" She glimpsed her lab notes. "Unless…"

Undyne squinted, puzzled. "Unless what?"

"…Maybe…I mean, since you're physically stronger than most other monsters, you might be able to hold out longer than the other subjects after—Undyne!"

"What's the plan?"

Alphys rummaged through one of her drawers and took out a key. "Follow me."

Undyne followed the scientist upstairs. Alphys cleared away her workstation and ran her fingers on the underside of the countertop until she felt something small and cold. Her eyes lit up for a moment as she inserted the key into the hidden lock.

The entire workstation unfolded to reveal numerous test-tubes and samples of a strange red substance. Undyne's eyes grew wide at the sight.

Alphys started searching through the test tubes. "Do you remember when I told you I was working on using science to find a way to break the barrier?"

"Yeah, but it was a dead end, wasn't it?"

Alphys shook her head. "Not entirely. I was able to successfully extract something from the human souls, the very thing that gives them the ability to persist after death." Alphys grinned as she held up one of the vials. "It might just be the extra 'oomph' you'll need to defeat this human."

Undyne pulled up a chair and took off the armor on her arm as Alphys filled a syringe with the contents of the vial. "And you've had this stuff hidden in case of an emergency?"

Alphys nodded. "Yes. It's dangerous, but we're in the middle of a crisis. We've gotta be willing to take risks to save our people."

Undyne looked over at her as she injected the liquid into Undyne's arm. Dammit, that hurt! Not the actual shot, but the liquid itself. It felt like it was burning her whole body, spreading the fire through her veins. She fell out of her chair and started writhing about on the floor in agony.

Alphys panicked. "Oh god oh god oh god oh god OH GOD!" She struggled to roll Undyne over and checked her pulse.

Undyne suddenly stopped convulsing and went limp

Alphys's heart sank.

"Un—Undyne?"

The fish-warrior let out a little groan as she opened her eyes. Alphys let out a sigh of relief. "Oh god, you're okay!" She threw her arms around Undyne in an embrace.

Undyne's face turned red. "Uh, Alphys? We're kinda on the ground here…"

Alphys realized suddenly that they were in a very compromising position, embracing on the ground. "Oh, right, sorry." Her face also flushed red as she stood up and dusted herself off. "So, uh, how do you feel?"

Undyne lifted herself off the ground and cracked her neck. The burning sensation hadn't gone away, but it wasn't painful anymore. It was warm and fierce and strong. It felt like something had lit her heart on fire and was spreading light and hope throughout her body.

"I feel—" she started to say, trying to think of the right word to express the new flame that was filling her with energy, "— _determined_."

The two went back downstairs. Undyne's eyes were all but glowing with this newfound power.

Alphys spoke, "Sans is keeping post over at the Capital if the human makes it that far. If—If things go wrong…"

"—Then there'll still be hope," Undyne finished. She placed a hand on Alphys's shoulder, making the smaller monster's face flush red again. "I don't know what's going to happen between me and the human. What I do know,"—she planted a kiss on Alphys's cheek—"Is that I'm not going to let that human get past me without dragging it through hell."

Alphys gazed at her, awe-stricken. "Un—Undyne…I—I'm…"

Suddenly, Alphys caught a flash of yellow in her peripheral and jerked her body to face the camera monitor.

The camera had picked up live footage from one of the caverns in Waterfall. The human was there, staring down a little monster child with a striped top.

Alphys's expression immediately transformed from one of awe to one of horror. "UNDYNE!" She yelled, spinning back to alert the warrior that there was one more monster in Waterfall who needed saving _NOW_.

But she had already left.

The heroine was on her way.

Alphys stared at the door and allowed herself to smile. She had complete faith in Undyne. It scared her to death to think of the unstoppable warrior dying in battle, but she knew in her head and her heart that Undyne would stop at nothing to protect the monsters of the underground.

That was one of the reasons why she loved her so much.

Alphys sighed wistfully. It was fun to pretend that in another world, things would be different. No monsters would have been hurt or killed, everybody's lives would still be peaceful and happy. And maybe she and Undyne would've—

 _No_ , she admonished herself. _It_ _'_ _s useless to think about all the if_ _'_ _s._

Especially now, she realized, as she heard someone sobbing from the other side of the door. She hit the button to let them in.

The yellow monster kid ran through the open door of the lab, tears streaming down his face and his entire body shaking in fear.

Alphys hit the lever to open the elevator and ushered the kid inside. Once they were both in, he collapsed in her arms.

"Undyne…She—She saved me," he stuttered.

Alphys gave him a warm smile. "Of course she did," she said, gently brushing the dirt off his shirt, "She's going to save us all."

 **A/N: I** **'** **ve never done a Genocide run, but I love that it is an option. Not because you get to kill all of your favorite characters, but because it reveals a completely different side to them that you don** **'** **t get to see in the Pacifist run. Any OOC-ness is intentional. For instance, the Temmies don** **'** **t speak in their normal hOi! language because they really are scared to death, and Undyne actually makes her move (kind of) on Alphys because this is probably going to be the last chance she** **'** **ll ever get to do so.**

 **Although I hate thinking of my babies going through so much pain and dying off, I really want to do more of these Genocide run one-shots.**

 **Thanks for all of you who are reading/reviewing/favoriting/whatevering!**


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